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Business Combinations - Summary of Unaudited Pro Forma Historical Results (Detail) - USD ($) $ / shares in Units, $ in Millions | 3 Months Ended
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Mar. 31, 2019 | Mar. 31, 2018
Business Combinations [Abstract] |  |
Total revenues | $ 1,993.0 | $ 1,855.9
Net earnings attributable to controlling interests | $ 334.3 | $ 275.6
Basic net earnings per share | $ 1.81 | $ 1.51
Diluted net earnings per share | $ 1.77 | $ 1.49

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